n.
or pulmonary emphysema
Abnormal distension of the lungs with air, usually associated with cigarette smoking and chronic bronchitis .
Elastic tissue degenerates, severely interfering with exhalation. Capillary walls disappear, leaving lung tissue dry and pale. The walls of the pulmonary alveoli (see pulmonary alveolus ) break down, so the lung fills with pools of air. Symptoms include severe breathlessness, weight loss, bluish skin, chest tightness, and wheezing. In bullous emphysema, the alveoli form large air cyst s that may rupture, causing lung collapse (see atelectasis ), or require surgery. Emphysema is irreversible; it normally continues to progress even after the cessation of smoking and may lead to death. See also pulmonary heart disease .